Pileus Git - ~andy/gtk/blob - gdk-pixbuf/gdk-pixbuf-loader.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
   2
   3 /* GdkPixbuf library - Main header file
   4  *
   5  * Copyright (C) 1999 The Free Software Foundation
   6  *
   7  * Authors: Mark Crichton <crichton@gimp.org>
   8  *          Miguel de Icaza <miguel@gnu.org>
   9  *          Federico Mena-Quintero <federico@gimp.org>
  10  *          Jonathan Blandford <jrb@redhat.com>
  11  *
  12  * This library is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Library General Public
  14  * License as published by the Free Software Foundation; either
  15  * version 2 of the License, or (at your option) any later version.
  16  *
  17  * This library is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with this library; if not, write to the
  24  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25  * Boston, MA 02111-1307, USA.
  26  */
  27
  28 #include "gdk-pixbuf-private.h"
  29 #include "gdk-pixbuf-loader.h"
  30 #include "gdk-pixbuf-io.h"
  31
  32 #include "gtksignal.h"
  33
  34 \f
  35
  36 enum {
  37         AREA_UPDATED,
  38         AREA_PREPARED,
  39         FRAME_DONE,
  40         ANIMATION_DONE,
  41         CLOSED,
  42         LAST_SIGNAL
  43 };
  44
  45 static GtkObjectClass *parent_class;
  46
  47 static void gdk_pixbuf_loader_class_init    (GdkPixbufLoaderClass   *klass);
  48 static void gdk_pixbuf_loader_init          (GdkPixbufLoader        *loader);
  49 static void gdk_pixbuf_loader_destroy       (GtkObject              *loader);
  50 static void gdk_pixbuf_loader_finalize      (GObject                *loader);
  51
  52 static guint pixbuf_loader_signals[LAST_SIGNAL] = { 0 };
  53
  54 \f
  55
  56 /* Internal data */
  57
  58 #define LOADER_HEADER_SIZE 128
  59
  60 typedef struct {
  61         GdkPixbuf *pixbuf;
  62         GdkPixbufAnimation *animation;
  63         gboolean closed;
  64         guchar header_buf[LOADER_HEADER_SIZE];
  65         gint header_buf_offset;
  66         GdkPixbufModule *image_module;
  67         gpointer context;
  68 } GdkPixbufLoaderPrivate;
  69
  70 \f
  71
  72 /* our marshaller */
  73 typedef void (* GtkSignal_NONE__INT_INT_INT_INT) (GtkObject *object,
  74                                                   gint arg1, gint arg2, gint arg3, gint arg4,
  75                                                   gpointer user_data);
  76 static void
  77 gtk_marshal_NONE__INT_INT_INT_INT (GtkObject *object, GtkSignalFunc func, gpointer func_data,
  78                                    GtkArg * args)
  79 {
  80         GtkSignal_NONE__INT_INT_INT_INT rfunc;
  81
  82         rfunc = (GtkSignal_NONE__INT_INT_INT_INT) func;
  83         (*rfunc) (object,
  84                   GTK_VALUE_INT (args[0]),
  85                   GTK_VALUE_INT (args[1]),
  86                   GTK_VALUE_INT (args[2]),
  87                   GTK_VALUE_INT (args[3]),
  88                   func_data);
  89 }
  90
  91 \f
  92
  93 /**
  94  * gdk_pixbuf_loader_get_type:
  95  * @void:
  96  *
  97  * Registers the #GdkPixubfLoader class if necessary, and returns the type ID
  98  * associated to it.
  99  *
 100  * Return value: The type ID of the #GdkPixbufLoader class.
 101  **/
 102 GtkType
 103 gdk_pixbuf_loader_get_type (void)
 104 {
 105         static GtkType loader_type = 0;
 106
 107         if (!loader_type) {
 108                 static const GtkTypeInfo loader_info = {
 109                         "GdkPixbufLoader",
 110                         sizeof (GdkPixbufLoader),
 111                         sizeof (GdkPixbufLoaderClass),
 112                         (GtkClassInitFunc) gdk_pixbuf_loader_class_init,
 113                         (GtkObjectInitFunc) gdk_pixbuf_loader_init,
 114                         /* reserved_1 */ NULL,
 115                         /* reserved_2 */ NULL,
 116                         (GtkClassInitFunc) NULL,
 117                 };
 118
 119                 loader_type = gtk_type_unique (GTK_TYPE_OBJECT, &loader_info);
 120         }
 121
 122         return loader_type;
 123 }
 124
 125 static void
 126 gdk_pixbuf_loader_class_init (GdkPixbufLoaderClass *class)
 127 {
 128         GObjectClass *gobject_class;
 129         GtkObjectClass *object_class;
 130
 131         object_class = (GtkObjectClass *) class;
 132         gobject_class = (GObjectClass *) class;
 133
 134         parent_class = gtk_type_class (gtk_object_get_type ());
 135
 136         pixbuf_loader_signals[AREA_PREPARED] =
 137                 gtk_signal_new ("area_prepared",
 138                                 GTK_RUN_LAST,
 139                                 GTK_CLASS_TYPE (object_class),
 140                                 GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, area_prepared),
 141                                 gtk_marshal_NONE__NONE,
 142                                 GTK_TYPE_NONE, 0);
 143
 144         pixbuf_loader_signals[AREA_UPDATED] =
 145                 gtk_signal_new ("area_updated",
 146                                 GTK_RUN_LAST,
 147                                 GTK_CLASS_TYPE (object_class),
 148                                 GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, area_updated),
 149                                 gtk_marshal_NONE__INT_INT_INT_INT,
 150                                 GTK_TYPE_NONE, 4,
 151                                 GTK_TYPE_INT,
 152                                 GTK_TYPE_INT,
 153                                 GTK_TYPE_INT,
 154                                 GTK_TYPE_INT);
 155
 156         pixbuf_loader_signals[FRAME_DONE] =
 157                 gtk_signal_new ("frame_done",
 158                                 GTK_RUN_LAST,
 159                                 GTK_CLASS_TYPE (object_class),
 160                                 GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, frame_done),
 161                                 gtk_marshal_NONE__POINTER,
 162                                 GTK_TYPE_NONE, 1,
 163                                 GTK_TYPE_POINTER);
 164
 165         pixbuf_loader_signals[ANIMATION_DONE] =
 166                 gtk_signal_new ("animation_done",
 167                                 GTK_RUN_LAST,
 168                                 GTK_CLASS_TYPE (object_class),
 169                                 GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, animation_done),
 170                                 gtk_marshal_NONE__NONE,
 171                                 GTK_TYPE_NONE, 0);
 172
 173         pixbuf_loader_signals[CLOSED] =
 174                 gtk_signal_new ("closed",
 175                                 GTK_RUN_LAST,
 176                                 GTK_CLASS_TYPE (object_class),
 177                                 GTK_SIGNAL_OFFSET (GdkPixbufLoaderClass, closed),
 178                                 gtk_marshal_NONE__NONE,
 179                                 GTK_TYPE_NONE, 0);
 180
 181         gtk_object_class_add_signals (object_class, pixbuf_loader_signals, LAST_SIGNAL);
 182
 183         object_class->destroy = gdk_pixbuf_loader_destroy;
 184         gobject_class->finalize = gdk_pixbuf_loader_finalize;
 185 }
 186
 187 static void
 188 gdk_pixbuf_loader_init (GdkPixbufLoader *loader)
 189 {
 190         GdkPixbufLoaderPrivate *priv;
 191
 192         priv = g_new0 (GdkPixbufLoaderPrivate, 1);
 193         loader->private = priv;
 194 }
 195
 196 static void
 197 gdk_pixbuf_loader_destroy (GtkObject *object)
 198 {
 199         GdkPixbufLoader *loader;
 200         GdkPixbufLoaderPrivate *priv = NULL;
 201
 202         g_return_if_fail (object != NULL);
 203         g_return_if_fail (GDK_IS_PIXBUF_LOADER (object));
 204
 205         loader = GDK_PIXBUF_LOADER (object);
 206         priv = loader->private;
 207
 208         if (!priv->closed)
 209                 gdk_pixbuf_loader_close (loader);
 210
 211         if (priv->animation)
 212                 gdk_pixbuf_animation_unref (priv->animation);
 213         if (priv->pixbuf)
 214                 gdk_pixbuf_unref (priv->pixbuf);
 215
 216         if (GTK_OBJECT_CLASS (parent_class)->destroy)
 217                 (* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
 218 }
 219
 220 static void
 221 gdk_pixbuf_loader_finalize (GObject *object)
 222 {
 223         GdkPixbufLoader *loader;
 224         GdkPixbufLoaderPrivate *priv = NULL;
 225
 226         loader = GDK_PIXBUF_LOADER (object);
 227         priv = loader->private;
 228
 229         g_free (priv);
 230
 231         if (G_OBJECT_CLASS (parent_class)->finalize)
 232                 (* G_OBJECT_CLASS (parent_class)->finalize) (object);
 233 }
 234
 235 static void
 236 gdk_pixbuf_loader_prepare (GdkPixbuf *pixbuf, gpointer loader)
 237 {
 238         GdkPixbufLoaderPrivate *priv = NULL;
 239
 240         priv = GDK_PIXBUF_LOADER (loader)->private;
 241         gdk_pixbuf_ref (pixbuf);
 242         g_assert (priv->pixbuf == NULL);
 243
 244         priv->pixbuf = pixbuf;
 245         gtk_signal_emit (GTK_OBJECT (loader), pixbuf_loader_signals[AREA_PREPARED]);
 246 }
 247
 248 static void
 249 gdk_pixbuf_loader_update (GdkPixbuf *pixbuf, guint x, guint y, guint width, guint height, gpointer loader)
 250 {
 251         GdkPixbufLoaderPrivate *priv = NULL;
 252
 253         priv = GDK_PIXBUF_LOADER (loader)->private;
 254
 255         gtk_signal_emit (GTK_OBJECT (loader),
 256                          pixbuf_loader_signals[AREA_UPDATED],
 257                          x, y,
 258                          /* sanity check in here.  Defend against an errant loader */
 259                          MIN (width, gdk_pixbuf_get_width (priv->pixbuf)),
 260                          MIN (height, gdk_pixbuf_get_height (priv->pixbuf)));
 261 }
 262
 263 static void
 264 gdk_pixbuf_loader_frame_done (GdkPixbufFrame *frame, gpointer loader)
 265 {
 266         GdkPixbufLoaderPrivate *priv = NULL;
 267
 268         priv = GDK_PIXBUF_LOADER (loader)->private;
 269
 270         priv->pixbuf = NULL;
 271
 272         if (priv->animation == NULL) {
 273                 priv->animation = g_new0 (GdkPixbufAnimation, 1);
 274                 priv->animation->n_frames = 0;
 275                 priv->animation->ref_count = 1;
 276                 priv->animation->width  = gdk_pixbuf_get_width  (frame->pixbuf) + frame->x_offset;
 277                 priv->animation->height = gdk_pixbuf_get_height (frame->pixbuf) + frame->y_offset;
 278         } else {
 279                 int w, h;
 280
 281                 /* update bbox size */
 282                 w = gdk_pixbuf_get_width (frame->pixbuf) + frame->x_offset;
 283                 h = gdk_pixbuf_get_height (frame->pixbuf) + frame->y_offset;
 284
 285                 if (w > priv->animation->width) {
 286                         priv->animation->width = w;
 287                 }
 288                 if (h > priv->animation->height) {
 289                         priv->animation->height = h;
 290                 }
 291         }
 292
 293         priv->animation->frames = g_list_append (priv->animation->frames, frame);
 294         priv->animation->n_frames ++;
 295         gtk_signal_emit (GTK_OBJECT (loader),
 296                          pixbuf_loader_signals[FRAME_DONE],
 297                          frame);
 298 }
 299
 300 static void
 301 gdk_pixbuf_loader_animation_done (GdkPixbuf *pixbuf, gpointer loader)
 302 {
 303         GdkPixbufLoaderPrivate *priv = NULL;
 304         GdkPixbufFrame    *frame;
 305         GList *current = NULL;
 306         gint h, w;
 307
 308         priv = GDK_PIXBUF_LOADER (loader)->private;
 309         priv->pixbuf = NULL;
 310
 311         current = gdk_pixbuf_animation_get_frames (priv->animation);
 312
 313         while (current) {
 314                 frame = (GdkPixbufFrame *) current->data;
 315
 316                 /* update bbox size */
 317                 w = gdk_pixbuf_get_width (frame->pixbuf) + frame->x_offset;
 318                 h = gdk_pixbuf_get_height (frame->pixbuf) + frame->y_offset;
 319
 320                 if (w > priv->animation->width) {
 321                         priv->animation->width = w;
 322                 }
 323                 if (h > priv->animation->height) {
 324                         priv->animation->height = h;
 325                 }
 326                 current = current->next;
 327         }
 328
 329         gtk_signal_emit (GTK_OBJECT (loader),
 330                          pixbuf_loader_signals[ANIMATION_DONE]);
 331 }
 332
 333 \f
 334
 335 /**
 336  * gdk_pixbuf_loader_new:
 337  *
 338  * Creates a new pixbuf loader object.
 339  *
 340  * Return value: A newly-created pixbuf loader.
 341  **/
 342 GdkPixbufLoader *
 343 gdk_pixbuf_loader_new (void)
 344 {
 345         return gtk_type_new (gdk_pixbuf_loader_get_type ());
 346 }
 347
 348 static int
 349 gdk_pixbuf_loader_load_module(GdkPixbufLoader *loader)
 350 {
 351         GdkPixbufLoaderPrivate *priv = loader->private;
 352
 353         priv->image_module = gdk_pixbuf_get_module (priv->header_buf, priv->header_buf_offset);
 354
 355         if (priv->image_module == NULL)
 356                 return 0;
 357
 358         if (priv->image_module->module == NULL)
 359                 gdk_pixbuf_load_module (priv->image_module);
 360
 361         if (priv->image_module->module == NULL)
 362                 return 0;
 363
 364         if ((priv->image_module->begin_load == NULL) ||
 365             (priv->image_module->stop_load == NULL) ||
 366             (priv->image_module->load_increment == NULL)) {
 367                 g_warning ("module %s does not support incremental loading.\n",
 368                            priv->image_module->module_name);
 369                 return 0;
 370         }
 371
 372         priv->context = (*priv->image_module->begin_load) (gdk_pixbuf_loader_prepare,
 373                                                            gdk_pixbuf_loader_update,
 374                                                            gdk_pixbuf_loader_frame_done,
 375                                                            gdk_pixbuf_loader_animation_done,
 376                                                            loader);
 377
 378         if (priv->context == NULL) {
 379                 g_warning("Failed to begin progressive load");
 380                 return 0;
 381         }
 382
 383         if( (* priv->image_module->load_increment) (priv->context, priv->header_buf, priv->header_buf_offset) )
 384                 return priv->header_buf_offset;
 385
 386         return 0;
 387 }
 388
 389 static int
 390 gdk_pixbuf_loader_eat_header_write (GdkPixbufLoader *loader, const guchar *buf, size_t count)
 391 {
 392         int nbytes;
 393         GdkPixbufLoaderPrivate *priv = loader->private;
 394
 395         nbytes = MIN(LOADER_HEADER_SIZE - priv->header_buf_offset, count);
 396         memcpy (priv->header_buf + priv->header_buf_offset, buf, nbytes);
 397
 398         priv->header_buf_offset += nbytes;
 399
 400         if(priv->header_buf_offset >= LOADER_HEADER_SIZE) {
 401                 if (gdk_pixbuf_loader_load_module(loader) == 0)
 402                         return 0;
 403         }
 404         return nbytes;
 405 }
 406
 407 /**
 408  * gdk_pixbuf_loader_write:
 409  * @loader: A pixbuf loader.
 410  * @buf: Pointer to image data.
 411  * @count: Length of the @buf buffer in bytes.
 412  *
 413  * This will cause a pixbuf loader to parse the next @count bytes of an image.
 414  * It will return TRUE if the data was loaded successfully, and FALSE if an
 415  * error occurred.  In the latter case, the loader will be closed, and will not
 416  * accept further writes.
 417  *
 418  * Return value: #TRUE if the write was successful, or #FALSE if the loader
 419  * cannot parse the buffer.
 420  **/
 421 gboolean
 422 gdk_pixbuf_loader_write (GdkPixbufLoader *loader, const guchar *buf, size_t count)
 423 {
 424         GdkPixbufLoaderPrivate *priv;
 425
 426         g_return_val_if_fail (loader != NULL, FALSE);
 427         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), FALSE);
 428
 429         g_return_val_if_fail (buf != NULL, FALSE);
 430         g_return_val_if_fail (count >= 0, FALSE);
 431
 432         priv = loader->private;
 433
 434         /* we expect it's not to be closed */
 435         g_return_val_if_fail (priv->closed == FALSE, FALSE);
 436
 437         if (priv->image_module == NULL) {
 438                 int eaten;
 439
 440                 eaten = gdk_pixbuf_loader_eat_header_write(loader, buf, count);
 441                 if (eaten <= 0)
 442                         return FALSE;
 443
 444                 count -= eaten;
 445                 buf += eaten;
 446         }
 447
 448         if (count > 0 && priv->image_module->load_increment)
 449                 return (* priv->image_module->load_increment) (priv->context, buf, count);
 450
 451         return TRUE;
 452 }
 453
 454 /**
 455  * gdk_pixbuf_loader_get_pixbuf:
 456  * @loader: A pixbuf loader.
 457  *
 458  * Queries the GdkPixbuf that a pixbuf loader is currently creating.  In general
 459  * it only makes sense to call this function afer the "area_prepared" signal has
 460  * been emitted by the loader; this means that enough data has been read to know
 461  * the size of the image that will be allocated.  If the loader has not received
 462  * enough data via gdk_pixbuf_loader_write(), then this function returns NULL.
 463  * The returned pixbuf will be the same in all future calls to the loader, so
 464  * simply calling gdk_pixbuf_ref() should be sufficient to continue using it.
 465  *
 466  * Return value: The GdkPixbuf that the loader is creating, or NULL if not
 467  * enough data has been read to determine how to create the image buffer.
 468  **/
 469 GdkPixbuf *
 470 gdk_pixbuf_loader_get_pixbuf (GdkPixbufLoader *loader)
 471 {
 472         GdkPixbufLoaderPrivate *priv;
 473
 474         g_return_val_if_fail (loader != NULL, NULL);
 475         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
 476
 477         priv = loader->private;
 478
 479         return priv->pixbuf;
 480 }
 481
 482 /**
 483  * gdk_pixbuf_loader_get_animation:
 484  * @loader: A pixbuf loader
 485  *
 486  * Queries the GdkPixbufAnimation that a pixbuf loader is currently creating.
 487  * In general it only makes sense to call this function afer the "area_prepared"
 488  * signal has been emitted by the loader.  If the image is not an animation,
 489  * then it will return NULL.
 490  *
 491  * Return value: The GdkPixbufAnimation that the loader is loading, or NULL if
 492  not enough data has been read to determine the information.
 493  **/
 494 GdkPixbufAnimation *
 495 gdk_pixbuf_loader_get_animation (GdkPixbufLoader *loader)
 496 {
 497         GdkPixbufLoaderPrivate *priv;
 498
 499         g_return_val_if_fail (loader != NULL, NULL);
 500         g_return_val_if_fail (GDK_IS_PIXBUF_LOADER (loader), NULL);
 501
 502         priv = loader->private;
 503
 504         return priv->animation;
 505 }
 506
 507 /**
 508  * gdk_pixbuf_loader_close:
 509  * @loader: A pixbuf loader.
 510  *
 511  * Informs a pixbuf loader that no further writes with gdk_pixbuf_load_write()
 512  * will occur, so that it can free its internal loading structures.
 513  **/
 514 void
 515 gdk_pixbuf_loader_close (GdkPixbufLoader *loader)
 516 {
 517         GdkPixbufLoaderPrivate *priv;
 518
 519         g_return_if_fail (loader != NULL);
 520         g_return_if_fail (GDK_IS_PIXBUF_LOADER (loader));
 521
 522         priv = loader->private;
 523
 524         /* we expect it's not closed */
 525         g_return_if_fail (priv->closed == FALSE);
 526
 527         /* We have less the 128 bytes in the image.  Flush it, and keep going. */
 528         if (priv->image_module == NULL)
 529                 gdk_pixbuf_loader_load_module (loader);
 530
 531         if (priv->image_module && priv->image_module->stop_load)
 532                 (* priv->image_module->stop_load) (priv->context);
 533
 534         priv->closed = TRUE;
 535
 536         gtk_signal_emit (GTK_OBJECT (loader),
 537                          pixbuf_loader_signals[CLOSED]);
 538 }
 539